In A there are visible traces of corrections to the R.H. triplet. Chopin initially wrote it half a tone lower, as in three analogous bar 94, 98 and 261. A side effect of the correction could have been an oversight of the 
restoring g2 in the 2nd half of the bar – in the initial version of this triplet the accidental was not necessary (see note next to this minim).
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category imprint: Corrections & alterations; Source & stylistic information
issues: Corrections in A, Errors resulting from corrections, Deletions in A, Main-line changes
notation: Pitch